body {
    background-color: black;
    width: 95%;
    margin: auto;
    color: white;
}

a{
    text-decoration: none;
    color: #fff;
}
ul{
    list-style-type: none;
}
em{
    font-style: normal;
}
.fl{
    float: left;
}
.fr{
    float: right;
}
.cf::after{
    content: "";
    display: block;
    clear: both;
}
.ibo{
    background: rgb(255, 255, 255);
    font-size: 19px;
    line-height: 23px;
    color: #000;
    padding: 6px 0px 6px 10px;
}
.ibt{
    color: #fff;
    background: #5d7fb9;
    padding: 6px 12px;
    font-size: 0.9em;
    line-height: 1.3em;
    opacity: 0.8;
}



.header {
    background: url('images/starfield-banner.jpg ');
    position: fixed;
    top: 0px;
    width: 100%;

    z-index: 1;

}

#imglogo{
    height: 90px;
    left: -20px;
}

#headerTop{
    width: 1200px;
    margin: 0 auto;
    padding: 25px 0px 0px 0px;

}

#input{
    width: 110px;
    height: 20px;
    padding: 10px 36px 10px 10px;
    background-color: #333;
    display: block;
    margin-top: 10px;
    outline: none;
    color: white;
}

#headerTop .input{
    position: relative;
}

.header .logo-link {
    padding: 10px;
}

.headerTop img{
    float: left;
}

.header .logo {
    width:110px;
    margin:11px;
}
#search{
    height: 30px;
    position: absolute;
    top: 32px;
    right: 5px;
}
#share{
    height: 30px;
    position: absolute;
    top: 32px;
    right: -25px;
}


.nav>li{
    float: left;
}
.nav>li>a{
    color:#fff;
    font-size: 18px;
    padding: 14px;
    display: inline-block;
    position: relative;
    border-right: 2px solid #666;
}

#headerTop .nav .last{
    border: 0;
    width: auto;
}

.nav2{
    float: left;
    margin: 0px auto;
    margin-top: 25px;
}
.nav2 li{
    float: left;
}
.nav2 li a{
    display: inline-block;
    height: 30px;
    position: relative;
    line-height: 30px;
    color: #fff;
    padding: 10px;
    font-size: 14px;
    background-color: #555;
}
#middle{
    padding-top: 10px;
    width: 1340px;
    margin: 150px auto 0 auto;
    position: relative;
}

#middle  .box-left{
    display: block;
    width: 660px;
    height: 615px;

    background-image: url(images/pia21924-16.jpg);
    background-size: 100%;
}

#middle .box-right-tl{
    /* margin-left: 700px; */
    clear: both;
    display: inline-block;
    width: 320px;
    height: 294px;
    position: absolute;
    top: 10px;
    right: 340px;
    background-image: url(images/mollweide_cycle.jpg);
}

#middle .box-right{
    width: 315px;
    height: 294px;
    background-color: #39719e;
    display: inline-block;
    position: absolute;
    top: 10px;
    right: 0px;
    padding-left: 8px;
}
#middle .box-right a{
    color: #fff;
    font-size: 14px;
    line-height: 16px;
    padding-right: 15px;
}

#middle .box-right h4{
    color: #fff;
    margin: 0px 10px;
    padding: 3px 0px 6px 0px;
    border-bottom: 1px solid #fff;
}
#middle .box-right .right-btm{
    position: absolute;
    left: 10px;
    bottom: 0px;
    border-top: 1px solid #fff;
}
/*
.middle .box .box-right-tr a{

}*/

#middle .box-right-b{
    /* margin-left: 700px; */
    display: inline-block;
    width: 660px;
    height: 300px;
    position: absolute;
    top: 324px;
    bottom: 0px;
    right: 0px;
    background-image: url(images/s69-39961.jpg);
    background-size: 100%;
}

.imgbtmo{
    width: 650px;
    position: absolute;
    left: 0px;
    bottom: -20px;
}
.imgbtmt{
    position: absolute;
    left: 0px;
    bottom: 35px;
}
.imgbtmth{
    position: absolute;
    left: 0px;
    bottom: 40px;
    /* text-decoration: underline; */
}
.imgbtmf{
    position: absolute;
    left: 0px;
    bottom: -20px;

}
#middle .box-left:hover .imgbtmo{
    background-color: #fff;
}
#middle .box-right-tl:hover .imgbtmf{
    background-color: #fff;
}
#middle .box-right-b:hover .imgbtmo{
    background-color: #fff;
}
.box-right-tr a:hover{
    text-decoration: underline;
}
.imgbtmth:hover,
.imgbtmt:hover{
    opacity: 1;
}

#middle2{
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: space-between;
    padding-top: 20px;
    width: 1340px;
    margin: 0px auto;
}

.m2 p a{
    color: #000;
}

.m2:nth-child(1){
    background-image: url(images/ssc2017-14a1.jpg);
    background-size: 100%;
    width: 330px;
    height: 300px;
    position: relative;
}
.m2:nth-child(2){
    background-image: url(images/pia22556-16.gif);
    background-size: 100%;
    width: 650px;
    height: 300px;
    position: relative;

}
.m2:nth-child(3){
    background-image: url(images/ssc2017-14a1.jpg);
    width: 330px;
    height: 300px;
    position: relative;

}
.Himgbtmo{
    position: absolute;
    left: 0px;
    bottom: -20px;
    /* width: 330px; */
}
.Himgbtmt{
    position: absolute;
    left: 0px;
    bottom: 0px;
    width: 640px;
}
.Himgbtmth{
    position: absolute;
    left: 0px;
    bottom: 0px;
    width: 320px;
}

.Himgbtmy{
    position: absolute;
    left: 0px;
    bottom: 36px;
}

.Himgbtmy2{
    position: absolute;
    left: 0px;
    bottom: 60px;
}
.Himgbtmy3{
    position: absolute;
    left: 0px;
    bottom: 16px;
}
.Himgbtmy:hover{
    opacity: 1;
}
.ihome:hover .Himgbtmo,
.ihome:hover .Himgbtmt,
.ihome:hover .Himgbtmth{
    background-color: #fff;
}
#middle3{
    display: flex;
    flex-direction: row;
    padding-top: 20px;
    width: 1340px;
    margin: 0px auto;

}
.ibtm{
    width: 330px;
    height: 300px;
    margin-right: 15px;
}
.ibtm p a{
    color: #000;
}
.ibtm:nth-child(1){
    background-image: url(images/nasa_logo.png);
    background-size: 100%;
    position: relative;
}
.ibtm:nth-child(2){
    background-image: url(images/io-home.gif);
    background-size: 100%;
    position: relative;


}
.ibtm:nth-child(3){
    background-image: url(images/cassini20170809.jpg);
    background-size: 100%;
    position: relative;
}
.ibtm:nth-child(4){
    background-image: url(images/fermiicecube_as.jpg);
    background-size: 100%;
    position: relative;
}
.ibtm:hover .Himgbtmo{
    background-color: #fff;
}

#bottom{
    padding-top: 20px;
    width: 1340px;
    margin: 0px auto;
}
#bottom .morebtm{
    display: block;
    width: 100%;
    height: 17px;
    text-align: center;
    color: #fff;
    background-color: #15418c;
    font-size: 17px;
    line-height: 20px;
    font-weight: 600;
    padding: 8px 0px 15px 0px;
}
#bottom .morebtm:hover{
    background-color: #39719e;
}

#foot{
    padding-top: 30px;
    width: 1340px;
    height: 130px;
    margin: 0px auto;
}
#foot .ffleft img{
    width: 80px;
    height: 67px;
    margin-left: 20px;
    float: left;
}
#foot .ftext{
    color: #fff;
    font-size: 14px;
}
#foot .footnav{
    float: right;
}
#foot .footnav li{
    margin-top: 30px;
    float: left;
}
#foot .footnav li a{
    color: #5d7fb9;
    margin-left: 20px;
}
#foot .footnav li a:hover{
    text-decoration: underline;
}